add example client for jack_thread_wait()

git-svn-id: svn+ssh://jackaudio.org/trunk/jack@1029 0c269be4-1314-0410-8aa9-9f06e86f4224

example-clients/Makefile.am

@@ -41,6 +41,8 @@ bin_PROGRAMS = jack_load \
 		   jack_midisine \
 		   jack_midiseq
 
+noinst_PROGRAMS = jack_thread_wait
+
 if HAVE_SNDFILE
 # note! jackrec_CFLAGS syntax not supported by automake-1.4
 sndfile_cflags = @SNDFILE_CFLAGS@
@@ -69,6 +71,10 @@ jack_metro_SOURCES = metro.c
 jack_metro_LDFLAGS = @OS_LDFLAGS@
 jack_metro_LDADD = ../libjack/libjack.la
 
+jack_thread_wait_SOURCES = tw.c
+jack_thread_wait_LDFLAGS = @OS_LDFLAGS@
+jack_thread_wait_LDADD = ../libjack/libjack.la
+
 jack_lsp_SOURCES = lsp.c
 jack_lsp_LDFLAGS = @OS_LDFLAGS@
 jack_lsp_LDADD = ../libjack/libjack.la

example-clients/tw.c

@@ -0,0 +1,202 @@
+/** @file simple_client.c
+ *
+ * @brief This simple client demonstrates the basic features of JACK
+ * as they would be used by many applications.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <jack/jack.h>
+
+jack_port_t *input_port;
+jack_port_t *output_port;
+jack_client_t *client;
+
+/* a simple state machine for this client */
+volatile enum {
+	Init,
+	Run,
+	Exit
+} client_state = Init;
+
+/**
+ * The process callback for this JACK application is called in a
+ * special realtime thread once for each audio cycle.
+ *
+ * This client follows a simple rule: when the JACK transport is
+ * running, copy the input port to the output.  When it stops, exit.
+ */
+int
+_process (jack_nframes_t nframes)
+{
+	jack_default_audio_sample_t *in, *out;
+	jack_transport_state_t ts = jack_transport_query(client, NULL);
+	
+	if (ts == JackTransportRolling) {
+		
+		if (client_state == Init)
+			client_state = Run;
+		
+		in = jack_port_get_buffer (input_port, nframes);
+		out = jack_port_get_buffer (output_port, nframes);
+		memcpy (out, in,
+			sizeof (jack_default_audio_sample_t) * nframes);
+		
+	} else if (ts == JackTransportStopped) {
+		
+		if (client_state == Run)
+			client_state = Exit;
+	}
+
+	return 0;      
+}
+
+int
+process (jack_nframes_t nframes, void* arg)
+{
+	jack_client_t* client = (jack_client_t*) arg;
+
+	while ((nframes = jack_thread_wait (client, _process (nframes))) != 0);
+}
+
+/**
+ * JACK calls this shutdown_callback if the server ever shuts down or
+ * decides to disconnect the client.
+ */
+void
+jack_shutdown (void *arg)
+{
+	exit (1);
+}
+
+int
+main (int argc, char *argv[])
+{
+	const char **ports;
+	const char *client_name;
+	const char *server_name = NULL;
+	jack_options_t options = JackNullOption;
+	jack_status_t status;
+
+	if (argc >= 2) {		/* client name specified? */
+		client_name = argv[1];
+		if (argc >= 3) {	/* server name specified? */
+			server_name = argv[2];
+			options |= JackServerName;
+		}
+	} else {			/* use basename of argv[0] */
+		client_name = strrchr(argv[0], '/');
+		if (client_name == 0) {
+			client_name = argv[0];
+		} else {
+			client_name++;
+		}
+	}
+
+	/* open a client connection to the JACK server */
+
+	client = jack_client_open (client_name, options, &status, server_name);
+	if (client == NULL) {
+		fprintf (stderr, "jack_client_open() failed, "
+			 "status = 0x%2.0x\n", status);
+		if (status & JackServerFailed) {
+			fprintf (stderr, "Unable to connect to JACK server\n");
+		}
+		exit (1);
+	}
+	if (status & JackServerStarted) {
+		fprintf (stderr, "JACK server started\n");
+	}
+	if (status & JackNameNotUnique) {
+		client_name = jack_get_client_name(client);
+		fprintf (stderr, "unique name `%s' assigned\n", client_name);
+	}
+
+	/* tell the JACK server to call `process()' whenever
+	   there is work to be done.
+	*/
+
+	jack_set_process_callback (client, process, client);
+
+	/* tell the JACK server to call `jack_shutdown()' if
+	   it ever shuts down, either entirely, or if it
+	   just decides to stop calling us.
+	*/
+
+	jack_on_shutdown (client, jack_shutdown, 0);
+
+	/* display the current sample rate. 
+	 */
+
+	printf ("engine sample rate: %" PRIu32 "\n",
+		jack_get_sample_rate (client));
+
+	/* create two ports */
+
+	input_port = jack_port_register (client, "input",
+					 JACK_DEFAULT_AUDIO_TYPE,
+					 JackPortIsInput, 0);
+	output_port = jack_port_register (client, "output",
+					  JACK_DEFAULT_AUDIO_TYPE,
+					  JackPortIsOutput, 0);
+
+	if ((input_port == NULL) || (output_port == NULL)) {
+		fprintf(stderr, "no more JACK ports available\n");
+		exit (1);
+	}
+
+	/* Tell the JACK server that we are ready to roll.  Our
+	 * process() callback will start running now. */
+
+	if (jack_activate (client)) {
+		fprintf (stderr, "cannot activate client");
+		exit (1);
+	}
+
+	/* Connect the ports.  You can't do this before the client is
+	 * activated, because we can't make connections to clients
+	 * that aren't running.  Note the confusing (but necessary)
+	 * orientation of the driver backend ports: playback ports are
+	 * "input" to the backend, and capture ports are "output" from
+	 * it.
+	 */
+
+	ports = jack_get_ports (client, NULL, NULL,
+				JackPortIsPhysical|JackPortIsOutput);
+	if (ports == NULL) {
+		fprintf(stderr, "no physical capture ports\n");
+		exit (1);
+	}
+
+	if (jack_connect (client, ports[0], jack_port_name (input_port))) {
+		fprintf (stderr, "cannot connect input ports\n");
+	}
+
+	free (ports);
+	
+	ports = jack_get_ports (client, NULL, NULL,
+				JackPortIsPhysical|JackPortIsInput);
+	if (ports == NULL) {
+		fprintf(stderr, "no physical playback ports\n");
+		exit (1);
+	}
+
+	if (jack_connect (client, jack_port_name (output_port), ports[0])) {
+		fprintf (stderr, "cannot connect output ports\n");
+	}
+
+	free (ports);
+
+	/* keep running until the transport stops */
+
+	while (client_state != Exit) {
+		sleep (1);
+	}
+
+	jack_client_close (client);
+	exit (0);
+}